The office of a Ukrainian TV channel, which has been complaining about threats coming from nationalists over its editorial policy, was attacked overnight with a grenade launcher.

The building of 112 Ukraine was damaged on Friday night by a grenade apparently fired from a single-shot launcher. Two people reportedly drove by the premises, fired the explosive at the big logo of the channel on the building wall and fled the scene, leaving the used launcher tube behind.

Nobody was hurt in the incident, although the blast was strong enough to cause some damage inside, according to the channel. The moment of the attack was caught on CCTV cameras.

Kiev police said they were investigating the attack as a terrorist act, but are yet to make any arrests in the case or identify the motive behind it. The channel called on Ukrainian authorities to act and stop criminals attacking it and announced it will ramp up security at the office.

The outlet earlier asked for protection by international press freedom organizations, the European Union and Ukraine's law enforcement, saying it received numerous threats from radical nationalists. The reported surge may have been triggered by the decision to air the documentaryRevealing Ukraine by Academy Award-winning director Oliver Stone.

The film details the political crisis and armed conflict in Ukraine and features, among other things, exclusive interviews with Russian President Vladimir Putin and Ukrainian politician Victor Medvedchuk, who has close ties with the owner of 112 Ukraine.

It fails to follow the narrative about the conflict preferred by the current government in Kiev, so the decision was harshly criticized in the country. Prosecutor General Yury Lutsenko even threatened the channel with prosecution.

"I declare this: any attempts ... to demonstrate the Russian propagandist film, which Medvedchuk's channel is advertising, will result in punishment," the top official said in a video address.

The actual owner of the channel, Taras Kozak, called the night grenade attack "the latest threat to independent media" and accused the Ukrainian authorities of dereliction of duty to protect journalists.

The most successful tyranny is not the one that uses force to assure uniformity but the one that removes the awareness of other possibilities, that makes it seem inconceivable that other ways are viable, that removes the sense that there is an outside.